Drilling apparatus

ABSTRACT

A sample drilling apparatus comprising an above ground unit and a drilling tube assembly which in operation is rotated about its longitudinal axis and advanced axially into the ground to be sampled by said above ground unit, said drilling tube assembly comprising a stem and a cutting head connected thereto at its lowermost end, said drilling tube assembly having a delivery passage therethrough for up-flow of sample dislodged by the cutting head and an air supply passage communicating with said delivery passage through an air transfer assembly located adjacent the lowermost end of said drilling tube assembly, and a mud supply passage communicating with the wall of the drilled hole, for supplying mud to the wall of the drilled hole, said delivery passage having an above ground sample outlet and said air supply passage and said mud supply passage respectively communicating with an above ground air inlet assembly, through which air may be forced into said air supply passage, through said air transfer assembly to pass up said delivery passage with said sample, and an above ground mud inlet assembly communicating with said mud supply passage.

[ Apr. 30, 1974 DRILLING APPARATUS Inventor: James Dehoney Murrell, 41Padstow Rd., 8 Mile Plains, Brisbane, Australia Filed: Aug. 10, 1972Appl. No.: 279,587

Primary Examiner--David H. Brown Attorney, Agent, or FirmAllison C.Collard [57] ABSTRACT A sample drilling apparatus comprising an aboveground unit and a drilling tube assembly which in operation is rotatedabout its longitudinal axis and ad- Cl 1 vanced axially into the groundto be sampled by said l l5 above' ground unit, said drilling tubeassembly com- [51] Int. Cl E2lb 3/02, E2lb 21/02 rising a stem and acutting head connected thereto at Field Of 'd 2, its lowermost end, saiddrilling tube assembly having a delivery passage therethrough forup-flow of sample dislodged by the cutting head and an air supply pas-[56] References Cited sage communicating with said delivery passageUNITED STATES PATENTS through an air transfer assembly located adjacentthe 1,862,260 6/1932 Edmunds 175 215 X loweYmQst end of said drilling l,Sembly, and a 2,234,454 3/1941 Richter... 175 215 mud Supply P sCommunicating Wlth the wallof 2,419,738 4/1947 s i h 175/215 X thedrilled hole, for supplying mud to 'the 'wall of the 2,494,803 I/ 1950Frost et al.. 175/215 X drilled hole, said delivery passage having anabove 2,657,016 1953 G a l 175/215 ground sample outlet and said airsupply passage and 3 5 8/1958 Failingm 175/215 X said mud supply passagerespectively communicating 3953-330 9/1962 Arthur 175/195 with an aboveground air inlet assembly, through 3 g E which air may be forced intosaid air supply passage, 3l55l79 11/1964 rs? 175,215 through said airtransfer assembly to pass up said de- 3'208'538 9/1965 pitchermn": Xlivery passage with said sample, and an above ground 3:208539 9/1965175/69 X mud inlet assembly communicating with said mud sup- 3,323,6046/1967 Henderson. 175/215 x p y P s 3,601,206 8/1971 Grantom 175/215 I3,664,441 5/1972 Carey 175 215 16 Claims 6 Drawmg Flgures P5 3 r'P/ JDRILLING APPARATUS This invention relates to improvements in andrelating to drilling apparatus and it has more particular reference tosample drilling apparatus for use in sampling sand or other softformations.

The invention has been devised to provide a sample drilling apparatusfor use in sandy areas and other soft formation areas, which willprovide contamination-free samples. Other objects and advantages of theinvention will hereinafter become apparent.

With the foregoing and other objects in view this invention residesbroadly in sample drilling apparatus comprising an above ground unit anda drilling tube assembly which in operation is rotated about itslongitudinal axis and advanced axially into the ground to be sampled bysaid above ground unit, said drilling tube assembly comprising a stemand a cutting head connected thereto at its lowermost end, said drillingtube assembly having a delivery passage therethrough for up-flow ofsample dislodged by the cutting head and an air supply passagecommunicating with saiddelivery passage through an air transfer assemblylocated adjacent the lowermost end of said drilling tube assembly, and amud supply passage communicating with the wall of the drilled hole, forsupplying-mud to the wall of the drilled hole, said delivery passagehaving an above ground sample outlet and said air supply passage andsaid mud supply passage respectively communicating with an above groundair inlet assembly, through which air may be forced into said air supplypassage through said air transfer assembly to pass up said deliverypassage with said sample, and an above ground mud inlet assemblycommunicating with said mud supply passage.

According to one feature of the invention the mud is supplied by forcingit down through the drilling tube assembly, suitably in a passagebetween concentric tubes, delivery means being provided, above thecutting head, from said passage to communicate with the wall of thedrilled hole. The said mud passage within the drilling assembly issuitably sealed from the air supply passage, the latter being locatedconcentrically inwardly of the mud passage.

According to another feature of the invention the above ground unit forrotating the drilling assembly includes drive means to rotate thedrilling assembly and inlet assemblies for mud and air to supply thesaid mud to the mud passage within the rotating drilling assembly andair to the air passage within the rotating drilling assembly and anoutlet passage from the delivery passage within the drilling assembly toenable the drilled and cut sample to be collected.

In order that the invention may be more readily understood and put'intopractical effect, reference will now be made'to the accompanyingdrawings which illustrate a preferred embodiment of the inventionwherein:

FIG. 1 is a partly schematic and sectional view of the above ground unitand the upper portion of the drilling tube assembly, according to oneembodiment of the invention;

FIG. 2 is a partly schematic part sectional view of the drilling tubeassembly and the cutting head according to one embodiment of theinvention;

FIG. 3 is an enlarged sectional view of cutting head illustrated in FIG.2;

FIG. 4 is a part sectional view of an alternate above ground unit andinlet assemblies for air and mud inlets into the drilling tube assembly;

FIG. 5 illustrates an alternate drilling tube assembly for use with thedrillinghead and inlet assemblies illustrated in FIG. 4; and I FIG. 6illustrates in cross-section a suitable sand bit for use with thedrilling tube assembly illustrated in FIG. 4 and FIG. 5.

Referring now to the drawings and in particular to FIGS. 1 to 3, thereis shown sample drilling apparatus 10 comprising a drilling tubeassembly 1 1 adapted to be rotated and advanced into the ground to besampled by an above ground unit 12. In this embodiment, the above groundunit 12 has an output shaft 13 which is, in operation, rotated by ahydraulic motor 14 driving through a two speed gearbox 15, containedwithin a main frame assembly 23. The normally vertical output shaftassembly 13' comprises an inner torque transmitting tube 16 which isdisposed concentrically within and secured to an intermediate tube 17and an outer tube 18. The outer passage 19 between the outer tube 18 andthe intermediate tube 17, forms the mud passage 19 through which mud issupplied to the drilled hole, and the passage 20 between theintermediate tube 17 and the torque tube 16 forms the air passage 20into which air is supplied under pressure. The top ends 21 of theconcentric tubes of the drive spindle assembly 13 engage sealably androtatably, by a glandular type connection as illustrated, withdownwardly projecting concentrically disposed dividing walls 22 fixedrigidly to the main frame 23. These dividing walls 22 form therebetweenan air inlet chamber 24, which remains stationary when the output shaft13 rotates and which communicates with the air passage 20, and a mudinlet chamber 25 which communicates with the mud passage 19. Theinnermost concentric wall 22 continues upwards to form an outlet passage26 onto which a length of flexible tube can be fixed to direct thecuttings to the sampling station.

The output shaft 13 connects to the drilling tube assembly 11 by meansof a quick-action threaded connection which interconnects the innertorque tubes 16 of the drive spindle assembly 13 and the drilling tubeassembly. As the tubes and passages in the drilling tube assembly 11 aresimilar to those of the output shaft 13 they will be referred to in thefollowing description with names and numerals denoted above for theoutput shaft. As is normal practice, the drilling tube assembly 1 1 ismade up of the required number of individual drilling tube lengths,connected end to end by quick-action screw threads to form a drillingtube assembly of the required length. I

A cutting heat 27 is connected to the drilling tube at the lowermost end28 of the drilling tube assembly 11 by means of a quick-action screwthread connection 29, shown clearly in FIG. 3. As illustrated, thecutting head 27 comprises a body portion 30 having a sample flow throat31 which extends from cutting tips 32 at the lowermost end thereof, tothe drilling tube assembly 13. This sample flow throat 31 communicateswith the interior of the torque tube 16 which forms the deliverypassagefor upflow of sample dislodged by the cutting head 27. Air supplied tothe air passage 20 of the drilling tube assembly 11 is fed into airtransfer passages 33 in the cutting head and is directed therefrom, up-

tube 16 to force cuttings dislodged by the cutting head 27 up throughthe inner tube 16 to the surface where'- upon it is directed to asampling station, through the outlet passage 26.

In order to ensure that the mud forced down the mud passage 19 does notcontaminate the sample, the cutting head 27 is provided with mud outlets34 located towards the top of, and above a shoulder 35 in the cuttinghead 27. The viscosity of the mud and the volume pumped into the hold isregulated to an amount which will fill up the gap between the drillingtube 13 and the side wall. Mud as herein referred to is chemical mudused as a sealant in drilling operations.

Thus, in operation, as the cutting head 27 is forced down through thestrata to be sampled, air is fed into the air passage 20 to force thecuttings up through the inner tube 16, and mud is pumped down throughthe mud passage 19 into the gap between the drilling tube assembly 11and the side walls of the hole cut by the cutting head 27. It will thusbe seen from the drawings and the description that the mud does not findits way into the underside of the cutting head and thus into the samplecuttings.

In the embodiment illustrated in FIG. 4, FIG. and FIG. 6 there is shownan alternate form of sample drilling apparatus a comprising a two-speedabove ground unit 120 having a quick-action threaded output shaft 40which is adapted to engage with an air inlet assembly 41. The air inletassembly 41 is provided with a fixed air inlet 42 which is fixed rigidlyto the above ground unit, and the drill stem rotates relative to saidair inlet assembly. A mud inlet assembly 43 engages threadedly with andbelow the first connector means 41 and it is provided with a fixed mudinlet 44 connected to the above ground unit. The lower tapered portionof the second connector means 43 is threaded to enable standard lengthsof drill stem 11a to be connected thereto.

As can be seen from the drawings, the air inlet assembly 41 is providedwith an internal annular arrangement air inlet passages 45 whichcommunicate with a circumferential groove 46 provided in the outercylindrical face 47 of the central connector means of assembly 41. Afixed air inlet housing 48 is located sealably around the face 47 toform an air inlet chamber 49 so that air supplied to the fixed housing48 will be directed into the air passages 45. This assembly provides fora glandular type seal (not shown) in each of the internal recesses 48aand 48b in the structure fixed housing 48. An extension of the airpassages 45 is formed in the mud inlet assembly 43 and is adapted, whenthe inlet assemblies 41 and 43 and the drilling stem assembly areoperatively connected, to transfer air from the first inlet means to theannular passage 20a formed between the inner torque tube 16a and theintermediate tube 17a of the drilling tube assembly.

Similarly, the mud inlet assembly 43 is provided with a fixed mud inlet44 whichcommunieates with an mud passages 50 disposed annularly aroundthe outside of the air passage 45. The mud passages '50 have outlets attheir lower ends which communicates with the mud inlet passage 19aformed between the intermediate tube 17a and the outer tube 18a.

The cutting heat 27a is connected to the lowermost end of the drillingtube assembly by means of a quickaction screw connection assembly29a'which is fixed to the cutting bit 52 by outer housing 53 whichincorpoof the bit 52. This flange directs the air upwards and inwardsinto the interior 55 of the cutting head. As is clear from FIG. 6, thearrangement provides a relatively large mouth 57 for the introduction ofmined sample and a reduced throat 58 for efficient air blast elevationof the sample up the inner or torque tube 16a of the drill sternassembly. The sample outlet is ejected at a station above the drillinghead assembly 10a.

In this embodiment the sealing and stabilizing mud is ejected into thestrata above the cutting head 27a. To this end, the upper end 59 of thecutting head is provided with a recess 60 which terminates the mudpassage 19a. An outlet is provided from this recess 60 to the drilledstrata.

Drilling apparatus asdescribed andillustrated will therefore be foundvery effective in achieving the ob jects for which the invention hasbeen devised, and the invention is to be understood to embrace allvariations and modifications within its scope and ambit, as defined bythe appended claims.

What is claimed is:

1. Sample drilling apparatus comprising an above ground unit and adrilling tube assembly which in oper ation is rotated about itslongitudinal axis and advanced axially into the ground to be sampled bysaid above ground unit, said drilling tube assembly comprising a stemand a cutting head connected thereto at its lowermost end, said drillingtube assembly having a delivery passage therethrough for up-flow ofsample dislodged by the cutting head and an air supply passagecommunicating with said delivery passage throughan air transfer assemblylocated adjacent the lowermost end of said drilling tube assembly, and amud supply passage communicating with the wall of the drilled hole, forsupplying mud to the wall of the drilledhole, said delivery passagehaving an above ground sample outlet and said air supply passage andsaid mud supply passage respectively communicating with an above groundair inlet assembly, through which air may be forced into said air supplypassage, through said air transfer assembly to pass up said deliverypassage with said sample,

and an above ground mud inlet assembly communicating with said mudsupply passage.

2. Sample drilling apparatus according -to claim 1, wherein said mudpassage communicates with the side wall of the drilled hole adjacent theconnection between said stem and said cutting head.

3. Sample drilling apparatus according to claim 1, wherein said stem isadapted'to be lengthened by adding extra stem lengths and each stemlength is connectable to the adjacent stem length in such manner thatthe said passages are formed continuously through said stem.

4. Sample drilling apparatus according to claim 3, wherein each saidstem length comprises three spaced apart concentric tubes, an outertube, an intermediate tube and an inner tube, said tubes being adaptedto engage with corresponding tubes in adjacent stern lengths to formthree concentric continuous passages, an innermost passage enclosed bythe inner tube, an intermediate passage between the inner tube and theintermediate tube, and an outer passage between the outer tube and theintermediate tube, said three passages comprising said delivery passage,said air supply passage and said mud supply passage.

5. Sample drilling apparatus according to claim 4, wherein saidinnermost passageforms said delivery passage, said intermediate passageforms said air supply passage and said outer passage forms said mudsupply passage.

6. Sample drilling apparatus according to claim 5, wherein said aboveground unit has a rotary output shaft which connects to said drillingtube assembly for selectively rotating said drilling tube assembly, andsaid above ground unit is reciprocable in a direction along the axis ofits output shaft for selectively advancing or withdrawing said drillingtube assembly into and/or from the ground.

7. Sample drilling apparatus according to claim 6, wherein said rotaryoutput shaft is tubular and connects to said inner tube to form an upperextension thereof, and said above ground sample outlet has a connectorassembly fixed to said above ground unit and connected sealably with theupper end of said rotary output shaft by means of a glandular typefitting.

8. Sample drilling apparatus according to claim 7-, wherein said outputshaft comprises three spaced apart concentric tubes which form upperextensions of said inner tube, said intermediate tube, and said outertube respectively, and wherein there is provided a glandular type airconnector assembly on said above ground unit, which connects sealably tothe upper end of the air supply passage in said rotary output shaft andwherein there is provided a glandular type mud connector assembly onsaid above ground unit which connects sealintermediate annular passagewhich forms a continuous extension of said air inlet passage, and anupper mud supply passage which communicates with said mud supplypassage, there being provided a glandular-type mud connection between afixed mud inlet and said upper mud supply passage in said rotary outputshaft.

11. Sample drilling apparatus according to claim 5, wherein said cuttinghead is substantially tubular and has a central sample flow throattherethrough which communicates with said delivery passage.

12. Sample drilling apparatus according to claim 1 1, wherein saidcutting head has an air transfer passage which communicates with saidair supply passage in said stem and said sample flow throat, said airtransfer passage providing said air transfer assembly.

13. Sample drilling apparatus according to claim 12, wherein said airtransfer passage, in operation, directs air upwards and inwards fromsaid air supply passage into said sample flow throat.

14. Sample drilling apparatus according to claim 13,

wherein there are provided a plurality of said air transfer passagesspaced around said sample supply throat.

15. Sample drilling apparatus according to claim 13, wherein said airtransfer passage has a continuous annular opening around said sampleflow' throat.

16. Sample drilling apparatus according to claim 15 wherein said sampleflow throat is frustro-conical shaped and opens out towards the base ofthe cutting head.

1. Sample drilling apparatus comprising an above ground unit and adrilling tube assembly which in operation is rotated about itslongitudinal axis and advanced axially into the ground to be sampled bysaid above ground unit, said drilling tube assembly comprising a stemand a cutting head connected thereto at its lowermost end, said drillingtube assembly having a delivery passage therethrough for up-flow ofsample dislodged by the cutting head and an air supply passagecommunicating with said delivery passage through an air transferassembly located adjacent the lowermost end of said drilling tubeassembly, and a mud supply passage communicating with the wall of thedrilled hole, for supplying mud to the wall of the drilled hole, saiddelivery passage having an above ground sample outlet and said airsupply passage and said mud supply passage respectively communicatingwith an above ground air inlet assembly, through which air may be forcedinto said air supply passage, through said air transfer assembly to passup said delivery passage with said sample, and an above ground mud inletassembly communicating with said mud supply passage.
 2. Sample drillingapparatus according to claim 1, wherein said mud passage communicateswith the side wall of the drilled hole adjacent the connection betweensaid stem and said cutting head.
 3. Sample drilling apparatus accordingto claim 1, wherein said stem is adapted to be lengthened by addingextra stem lengths and each stem length is connectable to the adjacentstem length in such manner that the said passages are formedcontinuously through said stem.
 4. Sample drilling apparatus accordingto claim 3, wherein each said stem length comprises three spaced apartconcentric tubes, an outer tube, an intermediate tube and an inner tube,said tubes being adapted to engage with corresponding tubes in adjacentstem lengths to form three concentric continuous passages, an innermostpassage enclosed by the inner tube, an intermediate passage between theinner tube and the intermediate tube, and an outer passage between theouter tube and the intermediate tube, said three passages comprisingsaid delivery passage, said air supply passage and said mud supplypassage.
 5. Sample drilling apparatus according to claim 4, wherein saidinnermost passage forms said delIvery passage, said intermediate passageforms said air supply passage and said outer passage forms said mudsupply passage.
 6. Sample drilling apparatus according to claim 5,wherein said above ground unit has a rotary output shaft which connectsto said drilling tube assembly for selectively rotating said drillingtube assembly, and said above ground unit is reciprocable in a directionalong the axis of its output shaft for selectively advancing orwithdrawing said drilling tube assembly into and/or from the ground. 7.Sample drilling apparatus according to claim 6, wherein said rotaryoutput shaft is tubular and connects to said inner tube to form an upperextension thereof, and said above ground sample outlet has a connectorassembly fixed to said above ground unit and connected sealably with theupper end of said rotary output shaft by means of a glandular typefitting.
 8. Sample drilling apparatus according to claim 7, wherein saidoutput shaft comprises three spaced apart concentric tubes which formupper extensions of said inner tube, said intermediate tube, and saidouter tube respectively, and wherein there is provided a glandular typeair connector assembly on said above ground unit, which connectssealably to the upper end of the air supply passage in said rotaryoutput shaft and wherein there is provided a glandular type mudconnector assembly on said above ground unit which connects sealably tosaid mud supply passage in said rotary output shaft.
 9. Sample drillingapparatus according to claim 7, wherein said above ground air inletassembly is adapted to be connected between said output shaft and saiddrilling tube assembly and comprises a housing having a centralthrough-passage which forms a continuous extension of said deliverypassage and an outer annular passage which communicates with said airinlet passage, there being provided a glandular-type air connectionbetween a fixed air inlet and said outer passage in said rotary outputshaft.
 10. Sample drilling apparatus according to claim 9 wherein saidabove ground mud inlet assembly is adapted to be connected between saidair inlet assembly and said drilling tube assembly and comprises ahousing having a central through passage which forms a continuousextension of said delivery passage and an intermediate annular passagewhich forms a continuous extension of said air inlet passage, and anupper mud supply passage which communicates with said mud supplypassage, there being provided a glandular-type mud connection between afixed mud inlet and said upper mud supply passage in said rotary outputshaft.
 11. Sample drilling apparatus according to claim 5, wherein saidcutting head is substantially tubular and has a central sample flowthroat therethrough which communicates with said delivery passage. 12.Sample drilling apparatus according to claim 11, wherein said cuttinghead has an air transfer passage which communicates with said air supplypassage in said stem and said sample flow throat, said air transferpassage providing said air transfer assembly.
 13. Sample drillingapparatus according to claim 12, wherein said air transfer passage, inoperation, directs air upwards and inwards from said air supply passageinto said sample flow throat.
 14. Sample drilling apparatus according toclaim 13, wherein there are provided a plurality of said air transferpassages spaced around said sample supply throat.
 15. Sample drillingapparatus according to claim 13, wherein said air transfer passage has acontinuous annular opening around said sample flow throat.
 16. Sampledrilling apparatus according to claim 15 wherein said sample flow throatis frustro-conical shaped and opens out towards the base of the cuttinghead.